The present invention refers to an apparatus for aligning and/or retaining pallets to be repaired and/or pallet elements, whereby the pallets comprise a plurality of top deck board members, stringer board members and bottom deck board members, whereby a bottom deck board member is attached to the stringer board members by means of connecting block members, and whereby the pallet elements are attached to each other by connector means, particularly by nails.
The German Patent Publication DE-A-43 08 580 discloses a method and an apparatus for repairing damaged pallets. The damaged pallet is positioned and fixed on a machine table with its top side facing downwards. Thereafter, the damaged connecting blocks and board members are cut out with a separating device that is movable in three coordinate axes. The separating device comprises a machine head provided with a vertically running drive shaft. At the end of the drive shaft, a rotating circular saw blade is attached. The diameter of the circular saw blade is chosen such that it is smaller than the distance between the rows of connecting block members extending in longitudinal direction. Thus, the circular saw blade can be moved into the space between two adjacent rows of connecting block members extending in longitudinal direction, with the result that the damaged elements of the pallet can be selectively sawn off. Upon separating the damaged elements, the connector means, —nails—, are cut through. After the damaged elements having been removed, the pallet is transferred to a supply and assembly station where the elements to be replaced are fed to the corresponding location and positioned. The real attachment of the new parts is performed by means of two nailing devices, simultaneously driving in nails from the top and from the bottom.
The German Patent Publication DE-A-198 22 229 also discloses a method and an apparatus for repairing damaged wooden pallets. According to this publication, in a first step, the damaged board members and/or skids are separated from the pallet to be repaired. In a second step, the new parts are aligned to the pallet and thereafter nailed thereto. In a further step, the pallets are pressed, such that nails not fully driven in and board members not fully seated are brought into proper position. The apparatus for performing these method steps comprises a feed conveyor for feeding in the pallets, a destacker for singularizing the pallets, a disassembly station for selectively separating damaged parts, an assembly station for replacing the damaged parts, a centering and nailing station for attaching the replaced parts as well as a pressing station for pressing in protruding nails and not fully seated board members. The centering and nailing station serves, amongst else, for exactly positioning the replacement skids and the replacement top deck board members. To this end, the centering and nailing station is provided with three centering channels adapted to receive the three skids of a pallet. The right side centering channel is provided with a fixed outer wall and with a wall movable under the influence of spring biased push members, while the central centering channel is provided with two movable side walls that are pressed inwards under the influence of spring biased push members. The spring forces of the two push members acting on the two side walls are dimensioned such that the central skid is positioned with regard to the fixed right side outer wall. Finally, the left side centering channel comprises a movable inner wall and a movable outer wall, both under the influence of a spring biased push member, whereby the outer wall is higher than the inner wall. Thereby, the objective should be realized that the entire pallet, including its left side skid, is pressed against the fixed side wall and, thereby, positioned.
It is the object of the present invention to improve an apparatus for aligning and/or retaining pallets to be repaired and/or pallet elements of the kind mentioned herein before in such a way that the pallet elements to be attached to a partially disassembled pallet and the possibly displaced and/or rotated pallet elements, particularly bottom deck board members and/or connecting block elements, are aligned in proper position and retained therein such that they can be attached in their desired nominal position by applying new connector members.
To meet these and other objects, the invention provides an apparatus for aligning and/or retaining pallets to be repaired and/or pallet elements, whereby the pallets comprise a plurality of top deck board members, stringer board members and bottom deck board members, whereby a bottom deck board member is attached to the stringer board members by means of connecting block members, and whereby the pallet elements are attached to each other by connector means, particularly by nails. According to the invention, the apparatus comprises at least one fixed lateral stop member and one movable lateral stop member for each bottom deck board member and/or for each connecting block member, whereby each of the movable lateral stop members is adapted to press the assigned bottom deck board member and/or the assigned connecting block member against the related fixed lateral stop member in such a way that the particular bottom deck board member and the particular connecting block member, respectively, is positioned at least with regard to a line extending perpendicular to the longitudinal axis of the pallet and retained in this position.
A further object of the invention is that the apparatus shall ensure that the exterior dimensions of the pallet are within predetermined limits. This object is met with an apparatus which further comprises at least one fixed longitudinal stop member and at least one movable longitudinal stop member, said at least each one fixed and movable stop members extending perpendicularly to said lateral stop members and adapted particularly to define the dimensional accuracy in longitudinal direction, and/or to align the top deck board members and/or the bottom deck board members with regard to the longitudinal axis of the pallet as well as to retain them in that position.